When you use the default authentication method, all authentication details are stored within your GitHub Enterprise Server instance. Built-in authentication is the default method if you don’t already have an established authentication provider, such as LDAP, SAML, or CAS.

LDAP lets you authenticate GitHub Enterprise Server against your existing accounts and centrally manage repository access. LDAP is a popular application protocol for accessing and maintaining directory information services, and is one of the most common protocols used to integrate third-party software with large company user directories.